When systemd-shutdown is run, shared propagation is not needed anymore. Making
mounts private allow to move mount points. This is needed to untangle cyclic
mounts.
There is a case that confuses systemd-shutdown: a filesystem has been moved to
a mount point which is part of another filesystem from an image from that
former filesystem. systemd-shutdown cannot unmount any of those two
filesystems. It needs first to move the filesystem containing the image of the
other out of the tree of that image.
Here we move leaf mount points when they are busy so that they do not block
parent mounts. We can only move leafs at each iteration since moving mount
points also move sub mount points which would invalidate we read from
`/proc/self/mountinfo`.
This returns an ssize_t, not an int. On populare archs that's the
difference between 64bit and 32bit. hence, let's be more careful here,
and not silently drop half the bits on the ground by assigning the
return value to "int".
As noticed by @malikabhi05:
https://github.com/systemd/systemd/pull/24754#discussion_r1062903159
These wrap RELOADING=1 and STOPPING=1 messages. The former is
particularly useful, since we want to insert the MONOTONIC_USEC= field
into the message automatically, which is easy from C but harder from
shell.
We are basically already there, just need to add MONOTONIC_USEC= to the
RELOADING=1 message, and make sure the message is generated in really
all cases.
And send READY=1 again when we are done with it.
We do this not only for "daemon-reload" but also for "daemon-reexec" and
"switch-root", since from the perspective of an encapsulating service
manager these three operations are not that different.
We converted to not using #ifdef for most of our defines because the syntax is
nicer and we are protected against typos and can set -Werror=undef. Let's do
the same for SD_BOOT. The define is nicely hidden in build.h for normal builds,
and for EFI builds we were already setting SD_BOOT on the commandline.
Our HAVE_* variables are defined to 0 or 1, so '#if defined(HAVE_*)' is always true.
The variable is not defined when compiling for EFI though, so we need the
additional guard.
Fixup for 3f92dc2fd4.
(I don't want to do something like add -DHAVE_EXPLICIT_BZERO=0 to the commandline
in src/efi/boot/meson.build, because this quite verbose. Our compilation commandlines
are very long already. Let's instead keep this localized in this one spot in the
source file.)x
This erase_obj() machinery looks like voodoo and creates an awful lot of
noise as soon as we get back to building with -O0. We can do this in a
more simple way by introducing a struct that holds the information we
need on cleanup. When building with optimization enabled, all this gets
inlined and the eraser vanishes.
Valentin David
Spindle Security
Lennart Poettering
Luca Boccassi
Jan Janssen
Yu Watanabe
Mike Yuan
Ludwig Nussel
Richard Phibel
Daan De Meyer
Zbigniew Jędrzejewski-Szmek
Kai-Chuan Hsieh
drosdeck
Ulrich Ölmann
msizanoen1